A study has found that bottled water contains far more plastic particles than previously thought.

We were far from our goal. Water from plastic bottles contains 100 times more tiny plastic particles than previously thought, according to a study published Monday.

For their work, the researchers used a completely new technique using lasers. They tested three water brands without disclosing their names: “We believe that all bottled water contains nanoplastics, so singling out some of them may be considered unfair,” explained Beizhan Yang.

The results showed that the water contained between 110,000 and 370,000 particles per liter, of which 90% were nanoplastics and the rest were microplastics. The most common type was nylon (likely from plastic filters used to purify water), followed by polyethylene terephthalate (PET), which is what the bottles are made from.

What are the health consequences?

This study, published in the journal PNAS, raises questions about potential health consequences. “If people are concerned about nanoplastics in bottled water, it is reasonable to consider alternatives such as tap water,” comments Beizhan Yang, co-author of the study. The researchers also hope to test tap water in the future, which also contains microplastics, but apparently in smaller quantities.

“We do not recommend not drinking bottled water when necessary, as the risk of dehydration may be greater than the potential effects of exposure to nanoplastics,” added Beizhan Yang.

In recent years, nanoplastics have attracted more and more attention and are present everywhere on the planet. Microplastics are less than 5,000 micrometers in size (or 5 mm), while nanoplastics are less than one micrometer in size. They are so small that they can penetrate the circulatory system and therefore organs, including the brain and heart.

Research into their effects on ecosystems and human health is still limited, but some studies have already identified harmful effects, for example on the reproductive system.